1. Field of the Invention
The present invention relates to an electrophotographic type image forming apparatus. More particularly, the present invention relates to a waste toner pulverizing apparatus and a toner cartridge with the same which pulverizes waste toner accumulated between a photosensitive drum and a front end of a cleaning blade.
2. Description of the Related Art
In general, an electrophotographic type image forming apparatus is a printing apparatus in which an electrostatic latent image formed on a surface of a photosensitive drum is developed by a toner to form a visible image. The developed visible image is then transferred to a printing media. After the visible image is transferred to the printing media, any toner that is not transferred to the printing media remains on the surface of the photosensitive drum. The remaining toner is waste toner that can not be used for developing new electrostatic latent images, and so the waste toner needs to be removed from the surface of the photosensitive drum. Accordingly, an electrophotographic type image forming apparatus includes a waste toner removing unit which can remove such waste toner.
Referring to FIG. 1, a waste toner removing unit 1 comprises a cleaning blade 3, a waste toner housing 5 and a waste toner transporting plate 7.
The cleaning blade 3 is installed so that it contacts the surface of a photosensitive drum 10 in an axial direction, and the cleaning blade 3 removes the waste toner remaining on the surface of the photosensitive drum 10. In general, the cleaning blade 3 has a rectangular plate shape and is made from an elastic material such as rubber.
The waste toner housing 5 receives the waste toner which is removed from a surface of the photosensitive drum 10 by the cleaning blade 3. The waste toner housing 5 is provided below the waste toner transporting plate 7 at one side of the cleaning blade 3 and has a size and shape for receiving the waste toner that falls from the waste toner transporting plate 7.
The waste toner transporting plate 7 is provided above the cleaning blade 3 and guides the waste toner removed from the surface of the photosensitive drum 10 by a front end 3a of the cleaning blade 3 to the waste toner housing 5. The waste toner transporting plate 7 has a thin plate shape, such as plastic film. The waste toner transporting plate 7 can be vibrated above the cleaning blade 3 in an axial direction of the photosensitive drum 10 (that is, in a direction perpendicular to a paper in FIG. 1) by a separate driving means (not shown). When the waste toner transporting plate 7 is vibrated from side to side like this, the waste toner removed by the cleaning blade 3 does not accumulate on the waste toner transporting plate 7 and is received smoothly in the waste toner housing 5.
In the waste toner removing unit 1 described above, once the photosensitive drum 10 is rotated, the waste toner remaining on the surface of the photosensitive drum 10 is removed from the surface of the photosensitive drum 10 by the front end 3a of the cleaning blade 3 and then transported to an upper side of the waste toner transporting plate 7. The waste toner transported to an upper side of the waste toner transporting plate 7 is received in the waste toner housing 5 by gravity or by vibration.
In this conventional waste toner removing unit 1, a step is formed between the front end 3a of the cleaning blade 3 and the surface of the photosensitive drum 10. In other words, waste toner removed from the surface of the photosensitive drum 10 accumulates at the front end 3a of the cleaning blade 3 as indicated by reference numeral 9 in FIG. 1. In particular, when a user leaves the image forming apparatus for a long time without performing a printing operation or when the image forming apparatus is placed in a low temperature and low humidity environment, accumulation of the waste toner becomes excessive. When the waste toner accumulates as described above, since the waste toner is not removed completely from the surface of the photosensitive drum 10, the surface of the photosensitive drum 10 is not cleaned very well. This causes staining of images on the printed media.
Also, when the waste toner transporting plate 7 located above the cleaning blade 3 is vibrated from side to side, it is impossible to prevent the waste toner from accumulating at the front end 3a of the cleaning blade 3 as described above. Therefore, the media on which the image is formed may be contaminated due to incomplete cleaning of the surface of the photosensitive drum 10. Accordingly, there is a need for an improved apparatus for removing waste toner from the surface of a photo sensitive drum.